酯化条件对脱臭馏出物中维生素E含量的影响

以油脂脱臭馏出物为原料,采用酸碱酯化工艺提取其中的维生素E,探讨了不同酯化条件下产物中维生素E含量及酸值的变化情况。通过单因素实验和正交实验确定最佳酯化工艺条件为:硫酸溶液质量浓度0.025 g/mL,碱液质量浓度0.008 g/mL,碱酯化前物料水分含量0.6%,碱酯化时间3 h。在此条件下,产物中维生素E含量为6.26%,酸值(KOH)由96.42 mg/g降至3 mg/g。     

棕榈油脱臭馏出物中生育酚及生育三烯酚的富集

采用工业化从大豆油脱馏出物中富集维生素E的工艺,对棕榈油脱臭馏出物中生育酚及生育三烯酚进行了富集。结果表明,采用酯化、酯交换、一次分子蒸馏、冷析、树脂吸附分离、二次分子蒸馏的工艺,可将棕榈油脱臭馏出物中生育酚及生育三烯酚含量从1. 29%浓缩到95%以上,收率可达70%以上。     

离子交换法提纯天然维生素E的工艺研究

天然维生素E是一种具有良好生理功能和药理价值的抗氧化剂,具有广阔的开发前景和市场需求.论述了油脂脱臭馏出物中天然维生素E的特性,对从大豆脱臭馏出物中提取天然维生素E的工艺进行了研究,提出了适合于工厂进行提取天然维生素E的工艺及工艺条件.采用以弱碱阴离子交换树脂对天然维生素E浓缩液进行纯化的工艺条件.考察了上样量、洗脱速度与洗脱剂对分离的影响,以天然维生素E的含量和回收率为评价指标.实验结果表明,弱碱阴离子交换树脂纯化天然维生素E的最佳操作条件为上柱量90mg/mL,洗脱液流速5mL/min,洗脱剂环己烷∶乙醇体积比为75 ∶ 25.天然维生素E含量可由原来的30%提高到90%以上,回收率达到80%以上.今后对天然维生素E的进一步深入研究会取得更好的工艺条件.     

响应面法优化生物酶法催化脱臭馏出物甲酯化

为实现脱臭馏出物绿色、清洁、高效甲酯化,达到环保生产的目的,通过单因素实验和响应面实验对生物酶法催化脱臭馏出物甲酯化反应的工艺条件进行了优化,测定了反应前后维生素E含量的变化,并将新工艺应用于实际生产线。结果表明：生物酶法催化脱臭馏出物甲酯化的最佳反应条件为加水量1%(以脱臭馏出物质量计)、甲醇用量11.5%(以脱臭馏出物质量计)、固定化脂肪酶用量0.3%(以脱臭馏出物质量计)、反应温度35.6℃,在最佳条件下反应8 h脱臭馏出物中游离脂肪酸酯化率达到92.59%,甘油酯酯化率达到94.95%;生物酶法催化脱臭馏出物甲酯化反应过程中维生素E损失少,收率达到93%;与浓硫酸催化甲酯化工艺相比,产品维生素E(50%维生素E)总收率提高了3.47百分点,植物甾醇总收率提高了3.26百分点。综上,生物酶法催化脱臭馏出物甲酯化,可以得到较高的酯化率,提高了产品维生素E和植物甾醇收率。     

响应面法优化维生素E提取工艺

以植物油脱臭馏出物经酯化、冷析、水洗过滤后的酯化液为原料,采用分子蒸馏工艺从酯化液中提取维生素E,通过响应面法分析分子蒸馏过程产生的馏出液中维生素E的含量和回收率,从而优化维生素E提取工艺参数。根据相关研究的经验,进料流量和蒸馏温度是非常重要的工艺参数,进料流量为2～6ml/min,蒸馏温度为90～140℃时,对维生素E提取作用显著。实验结果表明:蒸馏温度110℃,进料流量4.0ml/min,维生素E质量分数达13.32%,回收率达95.12%。在进料流量较低、蒸馏温度较高的条件下,优化分离条件可获得高浓度的维生素E。     

大豆油脱臭馏出物中同时提取角鲨烯、生育酚和植物甾醇的工艺研究

采用酯化—高真空蒸馏工艺路线,从大豆油脱臭馏出物中同时提取角鲨烯、生育酚及植物甾醇。考察酯化条件(甲醇、催化剂浓硫酸用量及反应时间)对酯化率、角鲨烯和生育酚含量的影响。优化得到的最佳工艺为:催化剂浓硫酸添加量0.5%,醇油摩尔比10∶1,反应温度70℃,反应时间120 min,大豆油脱臭馏出物酯化率达到98.2%,生育酚和角鲨烯保留率分别为97.7%和97.5%。酯化后的物料通过冷析结晶,抽滤得到植物甾醇粗品,滤液高真空蒸馏,初步分离得到脂肪酸甲酯、角鲨烯、生育酚等组分。各组分中角鲨烯富集到12.2%,生育酚富集到28.6%,植物甾醇富集到60%左右,初步实现了大豆油脱臭馏出物中角鲨烯、生育酚、植物甾醇的同时提取,为角鲨烯、生育酚及植物甾醇的进一步富集提供了参考依据。     

双低菜籽油脱臭馏出物提取天然VE的酯化工艺研究

探讨了从双低菜籽油脱臭馏出物中提取天然VE的酯化工艺条件,依据正交实验确定了第一次酯化的最佳工艺参数为:馏出物:甲醇(W/V)10:9,酯化温度60℃,酯化时间2 h;第二次酯化的最佳工艺参数为:甘油酯:甲醇(摩尔比)1:6,催化剂用量1.0%,酯化温度45℃,酯化率98.9%.     

脱臭馏出物提取VE的酶预处理

研究了以大豆油脱臭馏出物为原料,采用脂肪酶Novozym435为催化剂,催化脂肪酸与甲醇的酯化反应。反应最佳工艺条件为:反应试剂摩尔比(甲醇∶脱臭馏出物中游离脂肪酸)为2.2∶1,催化剂用量为2.5%,反应温度为35℃,反应时间为10 h。在最佳反应条件下酯化率为95.9%。     

水力空化强化大豆油脱臭馏出物酯化脱酸反应研究

大豆油脱臭馏出物是提取天然维生素E的重要原料。以大豆油脱臭馏出物为原料,在新型水力空化反应器内进行酯化脱酸研究,考察了空化元件入口压力、催化剂(浓硫酸)用量、循环流量和油醇空化体积比对酯化脱酸反应和维生素E收率的影响,并将水力空化混合技术与传统机械搅拌进行了对比。通过实验确定了水力空化反应器内酯化脱酸反应的最适参数:空化元件入口压力0.3 MPa,催化剂用量为油质量的3%,循环流量300 m L/min,油醇空化体积比5∶1;在上述最适参数条件下反应180 min酯化率可达到99%,维生素E的收率为99%。在相同原料配比条件下,与机械搅拌相比,水力空化强化混合条件下酯化率最高提高了12.1%。     

分子蒸馏技术提取茶油脱臭馏出物中维生素E

以茶油脱臭馏出物为原料,采用阳离子交换树脂催化酯化反应,然后将酯化产物进行三次分子蒸馏,逐步脱除脂肪酸和少量的其他杂质。通过正交试验法对分子蒸馏试验条件进行优化。结果表明,当蒸发温度为200℃,进料速率为4 m L/min,刮膜转速为150 r/min时,产物维生素E的纯度达到最高,为0.93%。应用高效液相色谱法对原料成分进行分析,建立了从原料到产品的维生素E含量分析方法,为生产维生素E提供技术参考。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the